// Scintilla source code edit control
/** @file PositionCache.h
 ** Classes for caching layout information.
 **/
// Copyright 1998-2009 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.

#ifndef POSITIONCACHE_H
#define POSITIONCACHE_H

#ifdef SCI_NAMESPACE
namespace Scintilla {
#endif

static inline bool IsEOLChar(char ch) {
    return (ch == '\r') || (ch == '\n');
}

/**
 */
class LineLayout {
private:
    friend class LineLayoutCache;
    int *lineStarts;
    int lenLineStarts;
    /// Drawing is only performed for @a maxLineLength characters on each line.
    int lineNumber;
    bool inCache;
public:
    enum { wrapWidthInfinite = 0x7ffffff };
    int maxLineLength;
    int numCharsInLine;
    int numCharsBeforeEOL;
    enum validLevel { llInvalid, llCheckTextAndStyle, llPositions, llLines } validity;
    int xHighlightGuide;
    bool highlightColumn;
    Selection *psel;
    bool containsCaret;
    int edgeColumn;
    char *chars;
    unsigned char *styles;
    int styleBitsSet;
    char *indicators;
    int *positions;
    char bracePreviousStyles[2];

    // Hotspot support
    int hsStart;
    int hsEnd;

    // Wrapped line support
    int widthLine;
    int lines;
    int wrapIndent; // In pixels

    LineLayout(int maxLineLength_);
    virtual ~LineLayout();
    void Resize(int maxLineLength_);
    void Free();
    void Invalidate(validLevel validity_);
    int LineStart(int line) const;
    int LineLastVisible(int line) const;
    bool InLine(int offset, int line) const;
    void SetLineStart(int line, int start);
    void SetBracesHighlight(Range rangeLine, Position braces[],
        char bracesMatchStyle, int xHighlight, bool ignoreStyle);
    void RestoreBracesHighlight(Range rangeLine, Position braces[], bool ignoreStyle);
    int FindBefore(int x, int lower, int upper) const;
    int EndLineStyle() const;
};

/**
 */
class LineLayoutCache {
    int level;
    int length;
    int size;
    LineLayout **cache;
    bool allInvalidated;
    int styleClock;
    int useCount;
    void Allocate(int length_);
    void AllocateForLevel(int linesOnScreen, int linesInDoc);
public:
    LineLayoutCache();
    virtual ~LineLayoutCache();
    void Deallocate();
    enum {
        llcNone=SC_CACHE_NONE,
        llcCaret=SC_CACHE_CARET,
        llcPage=SC_CACHE_PAGE,
        llcDocument=SC_CACHE_DOCUMENT
    };
    void Invalidate(LineLayout::validLevel validity_);
    void SetLevel(int level_);
    int GetLevel() const { return level; }
    LineLayout *Retrieve(int lineNumber, int lineCaret, int maxChars, int styleClock_,
        int linesOnScreen, int linesInDoc);
    void Dispose(LineLayout *ll);
};

class PositionCacheEntry {
    unsigned int styleNumber:8;
    unsigned int len:8;
    unsigned int clock:16;
    short *positions;
public:
    PositionCacheEntry();
    ~PositionCacheEntry();
    void Set(unsigned int styleNumber_, const char *s_, unsigned int len_, int *positions_, unsigned int clock);
    void Clear();
    bool Retrieve(unsigned int styleNumber_, const char *s_, unsigned int len_, int *positions_) const;
    static int Hash(unsigned int styleNumber, const char *s, unsigned int len);
    bool NewerThan(const PositionCacheEntry &other) const;
    void ResetClock();
};

// Class to break a line of text into shorter runs at sensible places.
class BreakFinder {
    LineLayout *ll;
    int lineStart;
    int lineEnd;
    int posLineStart;
    int nextBreak;
    int *selAndEdge;
    unsigned int saeSize;
    unsigned int saeLen;
    unsigned int saeCurrentPos;
    int saeNext;
    int subBreak;
    Document *pdoc;
    void Insert(int val);
public:
    // If a whole run is longer than lengthStartSubdivision then subdivide
    // into smaller runs at spaces or punctuation.
    enum { lengthStartSubdivision = 300 };
    // Try to make each subdivided run lengthEachSubdivision or shorter.
    enum { lengthEachSubdivision = 100 };
    BreakFinder(LineLayout *ll_, int lineStart_, int lineEnd_, int posLineStart_,
        int xStart, bool breakForSelection, Document *pdoc_);
    ~BreakFinder();
    int First() const;
    int Next();
};

class PositionCache {
    PositionCacheEntry *pces;
    size_t size;
    unsigned int clock;
    bool allClear;
public:
    PositionCache();
    ~PositionCache();
    void Clear();
    void SetSize(size_t size_);
    size_t GetSize() const { return size; }
    void MeasureWidths(Surface *surface, ViewStyle &vstyle, unsigned int styleNumber,
        const char *s, unsigned int len, int *positions, Document *pdoc);
};

inline bool IsSpaceOrTab(int ch) {
    return ch == ' ' || ch == '\t';
}

#ifdef SCI_NAMESPACE
}
#endif

#endif
